COGNITIVE-PROCESSES AND CEREBRAL CORTICAL FUNDI - FINDINGS FROM POSITRON-EMISSION TOMOGRAPHY STUDIES

Positron-emission tomography (PET) studies of regional cerebral blood flow have provided evidence relevant to localization of cognitive func tions. The critical loci identified in these studies are typically des cribed in terms of macroanatomically labeled cortical and subcortical regions. We report the results of a meta-analysis of localization of c hanges in blood flow, based on nearly 1000 cerebral cortical peaks of activity obtained from groups of subjects in 30 PET studies. The resul ts showed that, on average, 47% of these peaks were localized within t he fundus regions of cortical sulci. This is an unexpectedly high prop ortion because fundal regions compose <8% of the cortical mantle. Furt her analysis suggested a coarse correlation between the extent of fund al activation observed in different studies and the estimated cognitiv e complexity of the tasks used in the studies. These findings are pote ntially interesting because (i) the preponderance of fundal activation has implications for the interpretation of the PET data, (ii) they su ggest that cortical sulcal and fundal regions may play a distinctive r ole in higher cognitive processing, or (iii) both of the above.